Valve apparatus



Aug- 2, 1932 w. J. BOLTON 1,870,090

VALVE APPARATUS Filed May 7, 1929 2 sheets-sheen 2 WITNESSES INVENTOR Patented Aug. 2, 1932 MTEDKSTATES PATENT oFFlca WILLIAM J'. BOLTON, OFOAKLIONT, PENNSYLVANIA.

'VALVE APPARATUS Application led May 7, 1929. Serial No. 361,128. l

its action when the temperature of the chamber to be cooled reaches a predetermined low point and start its action againjwhen such temperature risesto a predetermined degree above such point., The starting and stopping of thecompressor accompanied by *20. la vstarting and stopping ofthelow of refrigerant into the 'cooling coil. 'In the operation of such systems, as usually-earned on, if a sufficient 'low of refrigerant is ladmltted to the coil, on thev original starting or on the restartingtof the compressor, to allow evaporation ofthe liquid refrigerant toA take place substantiall immediatel throughout the Whole length f the coil, At en, upon the't'emperature of the coil being lowered as the operation of the apparatus' proceeds',l evaporation of all theliquid re rigerant will not take place inthe coil, an increasing quantity of liquid particles passing beyond the end of the latter.y Suchxpassage of` liquid particles of refrigerant beyond the end pf the coil, besides indicating an inelicient operation of the system, 'resultsv in a disadvantageous frosting of the return line. Moreover, when lilquidparticles reach the compressor, over'- ltading oflthe latter results, and damage may, even occur;y

One manner of attempting to overcome the above difficulty has been to make the length of the cooling coilin excess of the actual,v re'l quirements dictated by the chamber being cooled and supply refrigerant only in sulficient amount to be initially evaporated in the beginning portion of such coil. The excess length of the coil thus provides space I or'the evaporation of the liquid particles which would otherwise pass the end of thev coil in the manner set forth above. Such an arrangement is not entirely effective in at taining its purpose, is ineii'icient, and in` volves that the refrigerating unit occupy a relatively large space, whereas it is a desiderl atum that the space takenup by such units be reduced to a minimum.

It is an object ofmy invention to provide a regulating valvefwhieh will admit re- GQ 'frigerant to the coil in such quantity that evaporation of the liquid'particles will take place substantially immediately throughout practically the Whole length of the coil, but Vwhich willnot permit the admission of re- Hfrigerantin suficient quantit for liquid par# ticles thereof to pass the en of the` coil. I attain thisobject b constructing the valve so that it is responsive both to the back pressure in the coil and to the temperature ofthe 70. outlet end of the coil. Thus when the temperature of the outlet end ofthe coil becomes lowered, due, for instance", to liquid particles of refrigerant being present and being evapo- A rated therein, the operation of the back pressure responsiveportion of the valve is modiiied in such manner'that less refrigerant is admitted to the coil, thereby remedying the condition. By this fmeans, the coil is allowed to operate at' all .times at high efficiency, 80 ad the valve is made morelsensitive generay., l Y v It is another object to provide a regulating valve having the above-named characteristic, in which no ill effects, such as flooding of the 35 cooling coil with liquid refrigerant,l will result from the temperature responsive portion of the'valve beingl subjected to an abnormally high' temperature, which abnormal tempera-l ture 'ma obtain Aupon occasion,l notabl at ,9 times o starting the admission of re rigerant to the coil. This result is obtained, according to my invention, by constructing4 the temperature responsive portion of the valve in such manner that upon its being actuated to a given extent bya rise of temperature in the outlet end of the coil, it will cease thereafter to'modify the action of the pressure responsive portion of the valve. y

Further objects are to provide against loss lo of sensitiveness of the temperature responsive portion of the valve by reason of part thereof reaching an undesirably low temperature; to insure further against frosting of the return line between the coil and the compressor, by warming the outlet end of the coil; to increase the eiiciency of the system, and reduce the sudden evaporation in the valve itself which occurs as the liquid refrigerant is admitted, by cooling the liquid refrigerant at or near the point where it isl admitted to the valve; and to provide a regulating valve which will be of a simple, economical and durable construction and which will be highly efficient and retain such eiiiciency under the varying conditions of use.

I have described by way of example in the following specification, and shown in the accompanying drawings, two forms of regulating valve in which my invention may be embodied. However, I wish it understood that the invention may be embodied in other forms, and that changes may be made in the forms described and shown, without exceeding the scope thereof as defined in the appended claims.

In the drawings:

Figure 1 is a diagrammatic View showing a refrigerating system of a well known type, with the form of my improved regulating valve shown in Figs. 2 4 installed therein;

Figure 2 is a sectional elevation of one form of regulating valve constructed in accordance with my invention;

Figure 3 is a sectional plan, the section being taken on the line III-III of Figure 2;

Figure 4 is an elevation of the valve shown in Figs. 2 and 3, looking from the left of Fig. 2; and

Figure 5 is a sectional elevation of another form of regulating valve constructed in accordance with my invention.

As shown in Fig. 1,` an ordinary type of refrigerating system, in which my improved valve is adapted to be used, comprises a compresser 1 the outlet side of which connects with one end of the coil 2 of a condenser in which the refrigerant collects in liquid form. The other end of the condenser coil 2 leads to the inlet end of the cooling coil 3. In ordinary usage, a valve, controlled by the back pressure in the cooling coil 3, is inserted in the line at the inlet end of such coil for varying the amount of liquid refrigerant admitted into the coil; and it is at this point that my improved valve is located in the system. The outlet end of the cooling coil is connected by a line with thc inletside of the compressor, which latter runs periodically, depending on the refrigeration requirement. According to my invention, this last named line has the temperature responsive portion of my valve connected therein, so that such portion is responsive to the temperature at the outlet end of the coolingcoil.

coil 3. For regulating the flow of refrigerant through the chamber 12 into the cooling coil, 3, the inlet opening 13 is formed with a valve seat 15, with which seat a valve 1G is arranged to cooperate. This valve is mounted 'upon a long st'em 17 which extends across the chamber 12 and is guided in a hole 18 formed in a plug 19 which is screwed into the casing 11.

In order to render the valve 16 responsive jointly both to the pressure in the chamber 12, which corresponds, of course, with the back pressure in the cooling coil, and to the temperature of the outlet end 3b of the cooling coil, a pair of flexible tubes 21 and 22 are provided, the disposition and operation of which will be described below.

The tube 21 is mounted at its upper end in a central hole formed in a disk 24 which is secured to the top of the casing 1l and forms a Cover for the chamber 12. The closed lower end of this tube extends into the chamber 12 and is acted upon by the pressure in the chamber, which pressure tends at all times to force the bottom end of the tube upwardly, .against the action of a spring 23 arranged between it and a member forming a bottom for the other flexible tube, 22. A bell crank lever 25 is pivoted on a pin 26 mounted in the chamber 12, and transmits to the valve 16 the movements of the tube 21. One arm of the lever is arranged to engage the bottom of the tube 21, which is made substantially rigid to that end, and the other arm is forked, at 27, to enclose the valve stem 17 and engage between a pair of collars 28 and 29 secured to the latter. A spring 3l engages between the collar 29 and the plug 19, and tends to force the valve 16 towards its scat 15, at the same time maintaining the bell crank lever in engagement with the bottom of the tube 21. Hence variations in pressure in the. chamber 12 will cause movements of the tube 21, the extent of which movements is dependent on the pressure exerted by the spring 23, and these movements will be communicated to the Valve 16 to cause the latter to approach or recede from its seat, as the case. may be. As will appear below. the pressure exerted by the spring 23 in the. tube 2l is varied by the action of the other tube, 22. the movements of which result from changes in temperature in the outlet end 37) of the cooling coil 3.

The second flexible tube, 22, which constitutes part of the temperature responsive portion of the valve, is mounted in a housing supported above the casing 11 by means of a base member 32 which is attached to the casing 11 by screws 33, which also hold the disk 24 in place. A hole 34 is formed, for the passage of the spring 23, in thev center of the base member 32. The above named housing is constituted by the base member 32, a capv 37 of correspondin size, and a pair of adjusting collars 35 and 36 rotatably mounted edgewise one`-on the other and held in place by flanges with which'the base member 32 and cap 37 are formed. These members are held together in such manner as to permit rotation of the collars 35 and 36 for adjustment purposes, by a pair of long screws 38 which pass through the cap 37 and are threaded into the base member 32 at 39. Upon an adjustment vot either or both collars having been made,

for purposes to be described below, the screws 38 are tightened, whereby the collars are secured in their adjusted position.

The upper end of the temperature responsive tube 22 is connected to the under side of the cap 37. lts lower end is constituted by the bottom of a cup 42 disposed in the upper portion of the housin so as to enclose the tube. The cup'42 is ormed with a rim 43 having holes 44 formed therein permitting the passage of the long screws 38 therethrough. ln this way any tendency of the cup 42 to'rotate is overcome, whilst still permittin an upward or downward movement thereo The chamber constituted by the interior of the tube 22 hasitherein a supply of fluid which, as will appear below, expands or contracts according to changes in temperature vof the outlet end 3b of the cooling coilf In order to vary the effect of such expansion or ycontraction in moving the cup 42 downward or upward (and In thereby modifying the pressure with which the spring 23 will act upon the tube 21), springs 45 are mounted on the screws 38 in engagement with the lower side of the rim 43. These springs are supported at their lower ends upon an eX- Jteriorly threaded ring 46 which is screwed into the hous'ng collar 35, the latter being internally threaded for the purpose. The 'ring 46 is held against rotating wlth the collar 35 by the screws 38, which pass through holes formed in the ring. Hence by turning the collar 35, the ring 46 may be raised or lowered to vary the force the springs 45 will exert upon the cup 42, whichs the force the pressure in chamber 40 must overcome in order to move the cup 42 downward, and thereby increase the eiect of the spring 23-on the other tube, 21.

In order to render the tube 22 responsive to the temperature of the outlet end of the cooling coil, a thermostat connection .between said tube and such outlet end is employed.

This connection comprises a pair of end members 49 and 51, to the member 49 of which is connected the outlet end 35 of the cooling coil, while to the member 51 the return line 5, extending from the cooling coil to the compressor, is connected. -Between these end members there is mounted an inner tube 52, which forms a continuation of the line and connects the outlet end 35 of the cooling coil with the end of the return l'ne 5, andan outer tube 53 which forms with the inner tube a chamber 55. The end member/51 is `formed with a shank 58 which is threaded upon a nipple 41, the latter being threaded into a central aperture formed in the cap 37. The shank and nipple are apertured to provide a central passage 57 therethrough which connects the chamber 55 with the chamber 40.

A supply of' a sutably expansible liquid, which liquid may conveniently be the refrigerant employed in the system, is placed in the tube 22 in such manner that the lower part of the chamber 40 constituted by such tube is occupied by the liquid, and the upper part of such chamber, togetherv with the chamber 55 which is in communication therewith, is occupied by the gas resulting from the evaporation of the fluid. Thus a rise in temperature of the tube 52 will result in an increase of pressure in the chambers 55 and 40, by reason of the expansionV of the gas and the formation of addit'onal gas by evaporation of the iuid, and a fall in temperature of the tube will result in a decrease of pressure, due to the contraction of the gas and the condensation of a part thereof- Thus the pressure in the chamber 40 reflects very sensitively the temperature of the tube 52.

To increase the conduction between the tube 52 and the gas in the chamber 55, a helical vane 56 is mounted on the outside of the tube; and to permit such condensate as is formed in the chamber 55 to run back into the chamber 4() the-tube 53 is so arranged that it slopes downwardly towards the passage 57. i

A nipple 59, having therein a central passage 61 which communicates with the passage 57, is formed on the shank 58 of the end member 51 to facilitate the charging of the tube-22 with liquid. Where the liquid employed is the condensed refrigerant used in the system, which is very convenient for the purpose, a branch may be connected be-r with a fitting 65 receiving the end of a tube 66 leading to the inlet 13 to the chamber 12.

Thus the refrigerant coming from the condenser 2, which is relatively warm by comparison with the usual temperature of the tube 52, willflow through the coil 63 and will impart heat to the fluid in the chamber 40, maintaining this chamber at a higher temperature than the chamber and insuring the sensitiveness of the device. By using the liquid refrigerant to war the thermally responsive fluid in the chamber 40, not only is the sensitiveness of the temperature responsive element maintained, but also the eiiiciency of the system is increased and troubles arising from the excessive cooling of the valve itself are avoided. In the usual valve, operating by back pressure, there is a sudden expansion of the re-` frigerant, which latter comes to the valve sometimes at approximately room temperature, when it enters the expansion chamber of the valve. This sudden expansion has no material usefulness for refrigeration purposes and is consequently wasteful. Moreover, in the ease of my improved valve, relatively great cooling of the valve itself by reason of such sudden expansion might injuriously affect the operation of the temperature responsive element. The entering re frigerant, by reason of being passed through the chamber 40, is materially cooled, and thus the suddenness of its expansion in the chamber 12 is reduced, with the consequence that the efficiency of the system is heightened and a reduction is made in the cooling of the valve by reason of this initial expansion.

The warning of the thermally responsive Huid in the chamber 40 by the coil 63 has the further advantage that the tube 52 is thereby warmed. The result `is a tendency of any moist particles which may attempt to pass the tube 52 to become evaporated at that point, whereby frosting of the return line is further guarded against.

The tube 22 is made of a considerably larger diameter than tube 21, so that relatively small changes in the temperature of the tube 52 at the outlet end of the cooling coil will have a relatively large effect in changing the pressure exerted by the spring 23 on the tube 21, and therefore a relatively large effect in modifying the action of the tube 21 in response to the pressure in the chamber 12. Thislcondition is desirable for the best operation of the valve. The relatively large diameter of the tube 22, however, makes it possible for the pressure produced in the chamber 40 under abnormal conditions to overbalance completely the pressure acting upon the tube 21. Consequently, the spring 23 at times might be compressed to such an extent as to make it impossible for the ressure obtainable in the chamber 12 to e ect the closing of valve 16 through the action of the tube 21. Such an abnormal pressure may occur when the refrigerating system is first started, at which time the heat responsive element is not infrequently heated to'a temperature considerably above its normal operating temperature. If the valve 16 were permitted to remain open for a considerable length of time, owing to the inability of the pressure in the chamber 12 to close it, because of the high compression of the spring 23 due to abnormal pressure in the chamber 40. the compressor and its motor` would be Isubject to damage by reason of the liquid refrigerant which would reach the compressor, and there would also result, of course, a material drop in the efficiency of the system. Moreover, the ahnormal pressure, above referred to, in the chamber 40 might even, in some circumstances, become so great as to wreck the tube 22. To provide against these possibilities, a stop ring 67 is screwed into the upper collar 36 of the housing, such collar being internally threaded for the purpose. This stop ring is disposed below the rim 43 of the cup 42 in such manner as to be engaged by such rim when the cup 42 has moved downward, under increase of pressure in the chamber 40, to a. predetermined extent. In this manner, excessive downward movement of the cup, with the possible resultsl aforesaid, is prevented. By turning of the housing collar 36, the stop ring 6T may be adjusted to limit positively the possible. downward movement of the cup 42 to any desired scope. Accordingly, by this adjustment. the device can be set so that the valve 16 will not he prevented, by abnormal pressure conditions-in the chamber 40 of the temperature responsive clement, from closing at a predetermined safe maximum back pressure.

The operation of the device is as follows: Supposing the compressor to have stopped its action, a condition of pressure, due to the expansion of the refrigerant remaining therein, will obtain in the cooling coil and chamber 12, and this pressure, acting on the tube 21, will be suiicient to hold the valve 16 against its seat, in spite of the fact that the cup 42, by reason of the fact that the temperature of the outlet end 3?) of the cooling coil may have becolne relatively high, may be seated against the ring 67 and thatconsequently the spring 23 may be-under extra compression. Upon the compressor starting again, the pressure in the cooling coil and chamber 12 will immediately be relieved and lll the spring 23 will be permittedl to open the valve 16, thus admitting liquid refrigerant into the chamber 12 andthe cooling coil. By a proper adjustment of the ring 46, the amount of refrigerant thus admitted is sufficient sothatevaporation will take place substantially immediately throughout practically the whole length of the coil. The outlet end 3b of the cooling coil will drop in temperature so long as evaporation takes place in or near` the same; and this drop in temperature is accompanied by a corresponding contraction of the tube 22,' upward movement of the cup 42 and relief of the spring 23, whereby the back pressure in the cooling coil and chamber 1,2 is permitted to move the valve 16 towards its seat to an increasing extent. Thus the drop-in temperature of the outlet end 3b of the cooling coil is accompanied by a corresponding diminution of the supply of refrigerant. This will continue until there is no further evaporation of refrigerant in or near the outlet end 3b of the cooling coil, and consequently no further material droplin the temperature of such outlet end. T us it is possible, in' starting the compressor, to supply refrigerant in suiiic-ient quantityto utilize substantially immediately practically the whole length of the cooling coil, and at the same time to avoid the passage of any material quantity of liquid refrigerant beond the outlet end of the cooling coil, with its attendant wasteful and harmful results. The embodiment of my invention shown in Fig. 5 differs from the embodiment described above chiefly in thatiiexible diaphragms are employed to provide pressure responsive chambers instead of flexible tubes. The bottom of the device constituting this embodiment isformedI by a casing 71 in which there is provided an inlet- 72 and an outlet 73. A partition 74 is arranged in the casing 71 between the inlet 72 and the outlet 73, and forms therein an inlet chamber 75 and an outlet or expansion chamber 76. Between these chambers is a passage in which there' is disposed a regulating valve 77. The top wall of the chamber 76 is constituted by a flexible diaphragm 78 which has a disk 79 mounted in its center against I-which the upper endof the stem 8.1 ofthe valve 77 bears. For urging the valve 77 towards a seat 82 formed in the passage 70,.and holding the valve stem 81 against the disk 79, a spring 83 is arranged betwee the bottom ofthe valve 77 anda plate 8 attached to the casing 71 at the bottom of the inlet chamber 75. The diaghragm 78 is held in place by a ring-like member 85 bolted to the top of casing71, with which it forms the base of the temperature responsive portion of the valve. Mounted one above the other on the member 85 are a pair of internally threaded collars 86 and 87, similar to the collars 35 and 36 of the preceding embodiment. On to of the collar 87 there is arranged a ring-li e memmovable plate 95, which, in turn, is supported l ony a pair of springs 96 mounted on the bolts 89. The springs 96 are supported on a movable ring 97 screwed in the collar 86, which ring may be adjusted, as in the previous embodiment, for varying the pressure of the springs. For flexibly transmitting to diaphragm`78 the movement of diaphragm 91 and also permitting the movement of diaphragm 78 without a corresponding movement in diaphragm 91, a spring. 98 is positioned between the bottom of plunger 94 and thev disk 79. To prevent the pressure in the chamber 93 from forcing diaphragm 91 too far downward, an exteriorly threaded stopring 99 which is adapted to engage the plate 95 is screwed into the adjustable collar 87. This ring operates in the same manner as the ring 67 of the preceding embodiment.

A connection with the outlet end of the cooling coil like that shown in Figs. 2-4 may be panded gases in the coolingvcoil of the system tending to close said valve,- thermostatic means adapted to be responsive to the tempera'ture of the refrigerant discharged from the cooling coils tending to open said valve in opposition to the pressure exerted on the valve closing means bythe expanded gases in the cooling coils, and adjustable means for predetermining the maximum back pressure necessary to close said valve.

2. In an automatically operable control device for refrigerating systems, a valve for controlling the flow of refrigerant in the system, means responsive to thepressure of the expanded gases in the cooling coil of the system tending to close said valve, thermostatic means adapted to be responsive to the temperature of the refrigerant discharged from the cooling coils tending to open said valvein opposition to the pressure exerted on the valve closing means by the expanded gases in the cooling coils, adjustable means for predetermining the maximum amountof pressure necessary to close said valve, and adjustable means for limiting the effect of the thermostatic means upon the valve closing means.

3. In an automatically operable control device for refrigerating systems, a valve for controlling the flow of refrigerant in the system, means responsive t0 the pressure of the expanded gases in the cooling coil of the system tending to close said valve, a thermostat device containing a thermally expansible fluid tending to open said valve in opposition to the pressure exerted onv said valve closing means by the pressure of the expanded refri gerant in the cooling coil, means for operatively connecting said thermostat device with the cooling coil adjacent the outlet end of the latter, whereby said fluid is responsive to the temperature of the refrigerant discharged from the cooling coil, and means for warming said thermally expansible fluid, to maintain the sensitiveness of said thermostat device.

4. In an automatically operable control device for refrigerating systems, a valve for controlling the flow of refrigerant in the system, means responsive to the pressure of the expanded gases in the cooling coil of the system tending to close said valve, a thermostat device containing a thermally expansible fluid tending to open said valve in opposition to the pressure exerted on said valve closing means by the pressure of the expanded refrigerant in the cooling coil, means for operatively connecting said thermostat device with the cooling coil adjacent the outlet end of the latter, whereby said fluid is responsive to the temperature of the refrigerant .discharged from the cooling coil, and means for utilizing the heat of the refrigerant employed in the system before it is expanded for warming said thermally expansible fluid, to maintain the sensitiveness of said thermostat device.

5. In an automatically operable contro device for refrigerating systems, a valve for controlling the flow of refrigerant in the system, means responsive to t-he pressure of the expended ga'ses in the cooling coil of the system tending to close said valve, a thermostat containing a thermally expansible fluid tending to open said valve in opposition to the pressure exerted on said valve closing means by the pressure or the expanded refrigerant in the cooling coils, means for operatively connecting said thermostat device withv the cooling coil adjacent the outlet end of the latter, whereby said fluid is responsive to the temperature of the refrigerant discharged from the coolingicoils, and a coil of pipe arranged insaid 'thermostat device through Which'a warming medium may be passed to heat said thermally expansible fluid, to mainpanded refrigerant in the cooling coils, means for connecting said thermostat device to the refrigerant lme of the system to render it vresponsive to the temperature of the refrigerant discharge, and means for passing unexpanded refrigerant through the fluid in said thermostat device, thereby to maintain the sensitiveness of said device, warm the 'discharge line and cool the unexpanded refrigerant.

7. An automatically operable control device for a refrigerating system comprising a casing having an expansible chamber arranged in both its upper and lower ends, each of said chambers being provided with an end wall adapted for vert-ical movement in response to variations in pressure conditions in said chambers, a springr member positioned between said vertically movable end Walls for transmitting the movement of one of said walls to the other, said lower chamber having an inlet and an out-let passage communicating therewith for connecting it in the refrigerant feed line of the system, a valve disposed in said inlet passage for controlling the flow of refrigerant therethrough, means connecting said valve to the movable end wall of said lower chamber whereby it is rendered responsive. to the pressure in both of said expansible chambers, a second spring member arranged in said casing with one end bearing upon the movable wall of said upper chamber and applying a force thereto in opposition to force exerted thereon by the pressure in that chamber, means Jfor varying the pressure said spring exerts upon said upper chamber wall, a thermally expansible fluid enclosed in said upper chamber, and means for rendering it responsive to the temperatnnl of the expanded refrigerant discharged from the cooling coils of the system. i

8. An automatically operable control de- 'vice for a refrigerating system comprising a casing having an expansible chamber arranged in both its upper and lower ends. each of said chambers being provided with an end wall adapted for vertical movement in response to variations in pressure conditions in said chambers, a spring member positioned between said vertically movable end walls for transmitting the movement of one of said walls to the other, said lower chamber having an inlet and an outlet passage communicating therewith for `connectin g it in the refrigerant feed line of the system, a valve disposed in said inlet passage for controlling the flow of refrigerant therethrough, means connecting said valve to the movable end wall of said lower chamber whereby it is rendered responsive to the pressure in both of said expansible chambers, a second spring member arranged in said casing with one end bearing upon the movable wall of said upper chamber and applying a force thereto in opposition to force exerted thereon by the pressure in that chamber, means for varying the pressure said spring exerts upon said upper chamber wall,

means for limiting the downward movement of the vertically movable wall of the upper chamber to limit its effect 'upon the operation of said valve, a thermally expansible fluid enclosed in said upper chamber, and means for rendering said fluid responsive to the temperature of the expanded refrigerant discharged from the cooling coils of the system.

9. An automatically operable control device for a refrilgerating system comprising a casing having an expansible chamber arranged in both its upper and lower ends, each of said chambers being provided with an end wall adapted -for vertical movement in response to variations in pressure conditions in said chambers, a spring member positioned between said vertically movable ends walls for transmitting the movement of one of said walls to the other, said lower chamber having an inlet and an outlet passage communicating therewith for connecting it in the refrigerant feed line of the system, a valve disposed in said inlet passage for controlling the ow of refrigerant therethrough, means connecting said valve to the movable end wall of said lower chamber whereby it is rendered responsive to the pressure in both of said expansible chambers, a second spring member arranged in said casing with one end bearing upon the movable wall of said upper chamber and applying a force thereto in opposition to force exerted thereon by the pressure in that chamber, means for varying the pressure said spring exerts upon saiduppgr chamber wall, means for limiting the downward movement of the vertically movable wall of the upper chamber to limit its effect upon the operation of said valve,athermally expansible fluid enclosed in said upper chamber, means for rendering said fluid responsive to the temperature of the expanded `refrigerant discharged from the cooling coil of the system,

and means 'for utilizing the heat in the liquid i refrigerant before it is expanded for warming the thermally expansible fluid in the upper chamber.-

10. An automatically operable control'device for a refrigerating system comprising a casing having an expansible chamber arranged in both its upper and lower ends, each of said chambers being provided with an end wall adapted for vertical lmovement in `response to variations in pressure conditions in said chambers, a spring member positioned between said vertically movable end walls for transmitting the movement of one of said walls to the other, said lower chamber having an inlet and an outlet passage communieating therewith for connecting it in the refrigerant feed line ofthe system, a valve disposed in said inlet passage for controlling the flow of refrigerant therethrough, means connecting said valve to the movable end wall of said lower chamber whereby it is rendered responsive to the pressure in both of said expansible chambers, a second spring member arranged in said casing with one end bearing upon the movable wall of said upper chamber and'applying a force thereto in opposition to force exerted thereon by the pressure in that chamber, means for varying the pressure said spring exerts upon said chamber wall, means for limiting the downward movevment of the verticallyvmovable wall of the upper chamber to limit its effect upon the operation of said valve, a thermally expansible fluid enclosed in said upper chamber, means for-rendering said fluid responsive to the temperature of the expanded refrigerant discharged from the cooling coil of the system, and a coil of pipe arranged in said upper.

chamber adapted to b e connected inthe refrigerant feed line and through which the liquidgrefrigerant is passed before it is expanded for the purpose of heating the expansible fluid in the upper chamber and cooling the refrigerant.

11. An automatically operable control device for a refrigerating system comprising a casing having an expansible chamber arranged in both its upper and lower ends, each of said chambers being provided with an end lwall adapted for vertical movement in response'to variations in pressure conditions in said chambers, a spring member positioned between said vertically movable end walls for transmitting the movement of one of said walls to the other, said lower chamber having an inlet and an outlet passage communicating therewith for connecting it in the refrigerant feed line of the system, a valve disposed in said inlet passage for controlling the'flow of refrigerant therethrough, means connecting said valve to the movable end wall of said lower chamber whereby it is rendered responsive to the pressure 1n both of said expansible chambers, a'second T spring member arranged 1n said casing with one end bearing upon the movable wall of said upper chamber and applying a force thereto in opposition to force exerted thereon by the pressure in that chamber, .means for varying the pressure said springexerts upon said upper chamber wall to regulate the opening and closing of said valve, means for limiting the downward movement of the vertical- 1y movable wall of the upper chamber to limit its effect upon the operation of said pressure in the cooling coils and the tempervalve, a thermally expansible fluid enclosed in said upper chamber, means disposed in the path of the expanded refrigerant discharged from the cooling coils of the system for rendering the thermally cxpansible fluid responsive to the temperature of the discharge refrigerant, and means for vapoi'izing liquid refrigerant tending to pass the point in the discharge line of the system where said temperature responsive means is located.

An automatically operable control device, Afor a refrigerating system comprising a casing constructed to form an expansion chamber, said casing having inlet and outlet passages arranged therein for connecting it in the refrigerant feed line of the system, a relatively small longitudinally expansible tube mounted in the upper part of such eX- paiision chamber, a valve disposed in said inlet passage, means connecting said valve to said expansible tube to render said valve responsive to the pressure conditions in such expansion chamber, a relatively large longitudinally expansible tube arranged above said casing, a thermally eXpansible fluid enclosed in said second-named tube, a casing communicating with said tube and adapte( to beI attached to the refrigerant line of the system above said secoiid-named tube, for

rendering the thermally expansible fluid in said secon d-named tube responsive to the temperature of the discharge gases from the cooling coils of the system, a spring arranged between the ends of said longitudinally eX- pansible tubes for transmitting the movement of one of the tubes to the other, to render the movement of said valve responsive to both the pressure of the expanded gases in the cooling` eoil of the system and the temperature. of the gases discharged therefrom, a second spring arranged to resist the downward movement of the lower end of said second-uan'ied tube, adjustable means for varying the pressure exerted by said last-named spring, and 'further adjustable means for limiting the downward movement of the lower end ot said second-named tube.

13. An automatically operable refrigerant controlling valve mechanism for refrigerating systems comprising a valve casing, a

*,valve member disposed in said casing for controlling the flow of refrigerant therethrough, automatically operable means for controlling` the operation of said valve and means' disposed in lsaid easing for utilizing the heat contained in the liquid refrigerant passed through the valve before it is eX- panded to heat the entire valve mechanism and thereby enhance its sensitivity under all conditions of operation.

l-l. lu an automatic control device for refrigerating systems. a valve member for controlling (he flow oi refrigerant through the 95 system. means iointly responsive to the back ature of the discharge refrigerant gases for automatically controlling the operationof said valve member and means for utilizing the heat contained in the liquid refrigerant 

